A constant challenge of urban building design is the limited amount space to contain a large number of people. Office and residential buildings optimize for a larger living space by adapting to architectural design that reduces wasted space, such as condominium, apartment, cubicle, and row offices. However, these conventional urban architectural designs lack adaptability. Because of the necessity to make each room similarly spaced, it is difficult to furnish each room with its own furniture and appliances that differentiate the rooms from one another.
Yet another challenge of the urban building design is the lack of space to lay out a construction site. Most urban construction sites are surrounded by many existing buildings. Because of the limitation on the size of a construction site, it is often difficult to build complicated building structures in an urban environment.